[prirun]

More fat per serving means less sugar per serving, for the same serving size. Skim milk has the highest sugar and carbs per serving. Skim milk will raise your glucose level; cream won't.

This is critical information they should teach kids in school so that they can understand how food works in their bodies.

[throwaway22032]

As someone who drinks a ton of whole milk (skimmed milk is for nancies), this sounds a bit off.

A glass of milk is the same serving size whether it's skimmed or whole milk. The latter has the same sugar and more fat.

Yoghurts seem to be more variable.

[austinjp]

Can you define what you mean by a serving? If the percentage of sugars is lower in skimmed milk (or full, whichever) then that will most likely raise blood glucose least, no?

There's also the personal factor to consider. Everyone has a unique metabolism. The only way to be sure is to take your fasted blood glucose levels then monitor your response after consuming a serving of a single food item. That food may raise one person's blood glucose more/faster than someone else's. Fortunately it's relatively easy to do this today for many people, although price and availability are variable.